Oscillating fluid compressor



Jan. 23, 1934. sMlTH 1,944,198

OSCILLATING FLUID COMPRESSOR Filed April 18,1932 2 Sheets-Sheet 1INVEIYTOR, 2 747? m ffi4- TORNEY Jan. 23, 1934.

Patented Jan. 23, 1934 UNITED STATES PATENT OFFICE Frank A. Smith, LosAngeles, Calif., assignor to Smith Manufacturing'Oompany, a corporationof Washington Application April 18, 1932. Serial No. 605,880

3 Claims.

This invention relates to gaseous fluid compressors and more especiallyto a fluid compressor particularly adaptable for the compression of agaseous refrigerant of the various kinds .,used in refrigeratingapparatus through which "the refrigerant is continuously circulated in acompressing and expanding cycle.

It is an object of the present invention to provide an extremely simple,practical, substantial and reliable fluid compressor, and further -toprovide a fluid compressor incorporating substantially only threeoperative elements, and a casing in which they are mounted and whichprovides a basin for retaining a lubricant for the operating parts aswell as providing space above the basin for the induction of the gaseousrefrigerant from an expansion device in its cycle or circuit.

More particularly, it is an object to provide 20.,a gaseous fluidcompressor in which there is in- --cluded a simple rotary driveroperating a simple plunger by direct interconnection and which operatesin a simple oscillating cylinder; the plunger and the cylinder operatingon the two .cycle induction and compression strokes.

A further object is to provide an automatic safety action which includesthe principal operating parts and is adapted to automatically act tobypass compressed fluid when a predeter- .,mined pressure has beenreached in the circulat- 'ing cycle of the compressed fluid.

The invention consists in certain advancements in this art as set forthin the ensuing disclosure and having, with the above, additional objectsand advantages as hereinafter developed, and

' *whose construction, combination and details of means, and the mannerof operation will be made manifest in the description of the herewithillustrative embodiment; it being understood that modifications,variations and adaptations may 'be resorted to within the scope,principle and spirit of the invention as it is more directly claimedhereinafter.

Figure 1 is a vertical section of a two unit com- 45, pressor on theplane of the axis of the driver.

Figure 2 is a cross section on line 2-2 of Fig. 1, and being transverseto the plane of Fig. 1.

Figure 3 is a sectional view showing a single unit compressor.

Figure 4 is a face view of a floating packing ring member.

Figure 5 is a detail of an intermediate guide and pressure devicebetween the compression cylinders of the multi-unit compressor.

65;; In its illustrated form, the compressor of Fig.

1 embodies a sealed casing 2 with a removable side plate 3 formingtherebetween a deep basin 4 for a lubricant 5 above which is a gaseousrefrigerant trap 6.

Extending through the upper portion of the casing is a drive shaft 7provided within the casing with a pair of diametrically oppositeeccentrics 8 and 9, though it is understood that any suitable number ofsuch eccentrics may be provided on the shaft 7.

The back wall of the casing has a bearing 10 receiving and covering thenear end of the shaft so that it does not extend through the casing 2while the opposite end of the shaft is supported in a bearing 11 at theouter side of which is a floating washer 12 on which seats one end of aspring 13 whose opposite endv thrusts outwardly against a running ring14 with an end bearing annulus 15 thrust against an outside cap 16suitably secured, as by screws 17, to the wall 3. The running ring 14has internal packing rings 18 snugly fitting the shaft '7.

A feature of this device is to insure thorough lubrication of thepacking ring element 15 against the inside face of the cap 16 throughwhich the shaft '7 extends. To such object, the packing ring is socombined with the shaft '7 as to travel in an orbital or sweeping zoneof contact against the'cap wall 16. In order to effect such sweepingmovement, the ring has an eccentric bore 14 in which the shaft is fittedfor relative movement. Thus the lubricant 5, passing the bearing 11 andentering the cap chamber in which the ring 14 rotates, will have accessto the zone of bearing of the annulus 15 and effectively lubricates thezone of bearing in a manner not possible where the relatively movingparts bear with an invarying zone of contact to which the lubricant isnot accessible. 1

On each eccentric 89 is an eccentric strap 20 having a radial plunger 21provided with suitable packing rings and operating in respectivecylinders 22 adjacent to the remote ends of which are discharge ports 23leading to a common discharge conduit 24 for conveying the compressedrefrigerant which is inducted into the compression cylinders 22 by anintake pipe 25 whose upper end opens near the top of the gaseous fluidtrap 6, and which connects with inlet ports 26 to the cylinders.

As shown, the cylinders have coaxial trunnions 27 in the casing 2 andwall 3 on which they oscillate, due to the eccentric action on theeccentric straps and plungers 21.

Means are provided for yieldingly thrusting the compression cylinders 22firmly against contiguous walls of the casing at bearing zones 28; thismeans providing a safety bypass from the discharge ports 23 back to thecasing in the event that pressure in the circulating system 2 l24'becomes higher than a predetermined desired maximum. Such means is shownas including a spring 30, in this case interposed between the adjacentsides of the cylinders 22 and expanding against them and thereby forcingthem to their bearing zones 28 with the desired pressure.

In Fig. 5 the spring 30 is shown as surrounding a bearing sleeve 31mounted on coaxial trunnions 32. In Fig. 3 only one of the compressingunits is shown in its sealed casing, this being a modification of thestructure.

From the above it Will be seen that each come pressor unit consistsessentially of but three principal operating elements, namely theeccentric device having a simple rotary movement, the eccentric drivenplunger 21 having a combined orbital and reciprocating movement, and thepivoted compression chamber having a simple oscillating movement on itstransverse trunnion axls.

As above stated, the desired factor of safety is accomplished by theyielding pressure acting on each compression cylinder and allowing it tomove to bypass compressed fluid back into the compression chamber. This,together with the effective leak-proof sealing device, provides, on thewhole, a highly effective, extremely simple, very low power consuminggaseous fluid compress-or, which while especially useful inrefrigcrating systems, is also adaptable to various other arts in whicha gas is compressed with or without continuous circulation.

What is claimed is: V

l. A gaseous fluid compressor comprising a plurality of oscillatorycompression cylinders, compression plungers operative therein, saidcylinders having lateral bearings operating on respective supports andhaving discharge ports opening to said bearings, and means interposedbetween and for yieldingly thrusting the cylinders against the bearingsand providing for automatic relief of pressure from the ports.

2. In a gaseous fluid compressor, a casing, a shaft passing through thecasing and having therewithin a plurality of eccentrics, eccentricstraps mounted thereon and having radial plungers, oscillatingcompression cylinders, with coaxial transverse bearings, and in whichcylinders said plungers reciprocate, said cylinders having adjacentsides provided with trunnions and a bearing device, and means forthrusting the cylinders yieldingly against bearing portions'in saidcasing; the cylinders having ports adapted to discharge back into thecasing when discharge pressure exceeds the seating effort of said thrustmeans. 7

3. A gaseous fluid compressor including a sealed 10 chamber and anoscillatory compression, cylinder therein, a rotatively driven eccentricin the chamher, and means connecting the said eccentric having a shaftpassing through the casing, a casing closure through which the shaftpasses and a sealing ring having projecting from an end face an annularbearing bead yieldingly pressed against said closure and being eccentricto the axis of the shaft.

FRANK A. SMITH.

